tpl: Fix the remaining template funcs namespace issues

See #3042

tpl/os/init.go

@@ -25,7 +25,7 @@ func init() {
 		ctx := New(d)
 
 		examples := [][2]string{
-			{`{{ range (readDir ".") }}{{ .Name }}{{ end }}`, `README.txt`},
+			{`{{ range (readDir ".") }}{{ .Name }}{{ end }}`, "README.txt"},
 			{`{{ readFile "README.txt" }}`, `Hugo Rocks!`},
 		}
 

tpl/os/os.go

@@ -35,9 +35,6 @@ type Namespace struct {
 	deps *deps.Deps
 }
 
-// Namespace returns a pointer to the current namespace instance.
-func (ns *Namespace) Namespace() *Namespace { return ns }
-
 // Getenv retrieves the value of the environment variable named by the key.
 // It returns the value, which will be empty if the variable is not present.
 func (ns *Namespace) Getenv(key interface{}) (string, error) {